/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.engine.impl.cmd;

import java.io.Serializable;

import org.activiti.engine.ActivitiException;
import org.activiti.engine.ActivitiIllegalArgumentException;
import org.activiti.engine.JobNotFoundException;
import org.activiti.engine.delegate.event.impl.ActivitiEventBuilder;
import org.activiti.engine.impl.cfg.TransactionState;
import org.activiti.engine.impl.context.Context;
import org.activiti.engine.impl.interceptor.Command;
import org.activiti.engine.impl.interceptor.CommandContext;
import org.activiti.engine.impl.jobexecutor.FailedJobListener;
import org.activiti.engine.impl.jobexecutor.JobExecutorContext;
import org.activiti.engine.impl.persistence.entity.JobEntity;
import org.flowable.common.engine.api.delegate.event.FlowableEngineEventType;
import org.flowable.common.engine.impl.interceptor.EngineConfigurationConstants;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Tom Baeyens
 * @author Joram Barrez
 */
public class ExecuteJobsCmd implements Command<Object>, Serializable {

    private static final long serialVersionUID = 1L;

    private static final Logger LOGGER = LoggerFactory.getLogger(ExecuteJobsCmd.class);

    protected String jobId;
    protected JobEntity job;

    public ExecuteJobsCmd(String jobId) {
        this.jobId = jobId;
    }

    public ExecuteJobsCmd(JobEntity job) {
        this.job = job;
    }

    @Override
    public Object execute(CommandContext commandContext) {

        if (jobId == null && job == null) {
            throw new ActivitiIllegalArgumentException("jobId and job is null");
        }

        if (job == null) {
            job = commandContext
                    .getJobEntityManager()
                    .findJobById(jobId);
        }

        if (job == null) {
            throw new JobNotFoundException(jobId);
        }

        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("Executing job {}", job.getId());
        }

        JobExecutorContext jobExecutorContext = Context.getJobExecutorContext();
        if (jobExecutorContext != null) { // if null, then we are not called by the job executor
            jobExecutorContext.setCurrentJob(job);
        }

        FailedJobListener failedJobListener = null;
        try {
            // When transaction is rolled back, decrement retries
            failedJobListener = new FailedJobListener(commandContext.getProcessEngineConfiguration().getCommandExecutor(), job.getId());
            commandContext.getTransactionContext().addTransactionListener(
                    TransactionState.ROLLED_BACK,
                    failedJobListener);

            job.execute(commandContext);

            if (commandContext.getEventDispatcher().isEnabled()) {
                commandContext.getEventDispatcher().dispatchEvent(ActivitiEventBuilder.createEntityEvent(
                        FlowableEngineEventType.JOB_EXECUTION_SUCCESS, job), EngineConfigurationConstants.KEY_PROCESS_ENGINE_CONFIG);
            }

        } catch (Throwable exception) {
            failedJobListener.setException(exception);

            // Dispatch an event, indicating job execution failed in a try-catch block, to prevent the original
            // exception to be swallowed
            if (commandContext.getEventDispatcher().isEnabled()) {
                try {
                    commandContext.getEventDispatcher().dispatchEvent(ActivitiEventBuilder.createEntityExceptionEvent(
                            FlowableEngineEventType.JOB_EXECUTION_FAILURE, job, exception), EngineConfigurationConstants.KEY_PROCESS_ENGINE_CONFIG);
                } catch (Throwable ignore) {
                    LOGGER.warn("Exception occurred while dispatching job failure event, ignoring.", ignore);
                }
            }

            // Finally, Throw the exception to indicate the ExecuteJobCmd failed
            if (!(exception instanceof ActivitiException)) {
                throw new ActivitiException("Job " + jobId + " failed", exception);
            } else {
                throw (ActivitiException) exception;
            }
        } finally {
            if (jobExecutorContext != null) {
                jobExecutorContext.setCurrentJob(null);
            }
        }
        return null;
    }

    public String getJobId() {
        return jobId;
    }

}
